From the Wood Shop
Collect all your natural wood sawdust, chips and shavings and haul them out to the compost pile. (Wear a mask because the dust will go “poof” when you throw it down and stir it.) Don’t compost dust, scraps, or shavings treated lumber because they contain chemicals you don’t want your tomatoes to grow in. Interestingly, the urea formaldehyde used in MDF resins is also used as a synthetic fertilizer, but I’d still avoid using it and other sheet goods for compost as well – just in case.
When you set up shop for treated lumber and sheet goods, take all your good, natural wood waste out to the compost bin, throw it on, and give it a quick mix. Then, when you set up shop again for natural wood, take all your “bad wood” dust and debris out to the trash so you can start collecting the good stuff again.
That said, it’s important to note that some trees produce chemicals that other plants don’t like. Butternut and Black Walnut, for example, produce a chemical called juglone, which is a fungicide and antibiotic, but also tends to kill tomatoes, peppers, eggplant and some other plants. While it’s certainly not a good idea to spread fresh Black Walnut sawdust to mulch your tomato crop, it’ll be okay if it’s left to cook in a compost heap for several months. This is because juglone breaks down under the same conditions in which compost thrives and cooks. A good way to test your compost for this toxin is to plant a tomato seedling in it and see what happens.
